KR101439675B1 - Cr-FREE SURFACE TREATMENT COMPOSITIONS AND SURFACE TREATED GALVANIZED STEEL SHEET USING THEREOF - Google Patents

Abstract

The present invention relates to a chrome-free surface treatment composition excluding chromium (Cr) which is a harmful substance, and a hot-dip galvanized steel sheet coated with the same.
There is an effect of providing a steel sheet excellent in corrosion resistance, blackening resistance and transparency by forming a coating on the plating layer of the coated steel sheet using the chrome-free surface treatment composition according to the present invention.

Description

Technical Field [0001] The present invention relates to a chrome-free surface treatment composition and a hot-dip galvanized steel sheet coated with the same. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a chrome-free surface treatment composition excluding chromium (Cr) which is a harmful substance, and a hot-dip galvanized steel sheet coated with the same.

The hot-dip galvanizing material containing magnesium (Mg) and aluminum (Al) is known as a steel material having excellent red rust corrosion resistance. Since the hot-dip galvanizing material is mostly made of Zn or Zn alloy, When exposed, white rust easily occurs on the surface, and Mg and Al in the molten plated material are more hygroscopic than Zn, so that discoloration easily occurs in which the surface color changes to black rather than the general molten plating material.

In order to solve such a problem, conventionally, chromium or chromate treatment has been applied to the galvanized steel sheet to secure corrosion resistance and black weather resistance. However, since chromium has been designated as a harmful environmental substance, it is not used at present, There has been a problem of defects such as black or black spots.

Therefore, at present, a method of applying a chromium-free resin instead of chromium or chromate treatment to impart corrosion resistance to the steel sheet is applied.

For example, Patent Documents 1 and 2 have developed a coating composition containing aluminum oxide in the form of tannic acid, an aromatic carboxylic acid such as sodium acetate, sodium borate, imidazole or the like, a surfactant, etc. However, There is a problem of deterioration. In Patent Document 3, a coating composition composed of zirconium carbonate, vanadium ion, zirconium compound and the like has been developed. However, this composition has a problem that the corrosion resistance is good but the surface blackening is poor.

Patent Document 4 proposes a technique of improving corrosion resistance and blackening with a composition composed of molybdic acid, ammonium, water-dispersed urethane resin, isopropylamine, ammonium zirconium carbonate, epoxy silane coupling agent and silica sol, There is a problem that the post-treatment coating film is thick and the conductivity is lowered.

Japanese Patent Application Laid-Open No. 53-28857 Japanese Laid-Open Patent Publication No. 51-71233 Japanese Laid-Open Patent Publication No. 2002-332574 Japanese Patent Application Laid-Open No. 2005-146340

One aspect of the present invention provides a surface treatment composition that does not contain a heavy metal such as hexavalent chromium which is a harmful substance and uses the chromium-free composition to manufacture a hot-dip galvanized steel sheet excellent in corrosion resistance, And to provide a way to do that.

An aspect of the present invention relates to a composition,

a) 50 to 80% by weight of a water-soluble organic-inorganic hybrid resin,

b) rustproofing corrosion resistance 1-10% by weight,

c) 5 to 20% by weight of an inorganic metal sol,

d) from 1 to 20% by weight of a metal chelate,

e) 5 to 20% by weight of a curing agent,

f) 1 to 10% by weight of a lubricant, and

And the remainder contains the residual solvent amount.

Another aspect of the present invention is a chromium-free surface treatment composition, wherein a coating layer of the chrome-free surface treatment composition is formed on one side or both sides of a hot-dip galvanized steel sheet, and the coating layer has a dry film thickness of 0.3 to 2.0 μm. There is provided a hot-dip galvanized steel sheet coated with a treating composition.

There is an effect of providing a steel sheet excellent in corrosion resistance, blackening resistance and transparency by forming a coating on the plating layer of the coated steel sheet using the chrome-free surface treatment composition according to the present invention.

Hereinafter, the chrome-free surface treatment composition according to the present invention and the hot-dip galvanized steel sheet coated with the chromium-free surface treatment composition will be described in detail.

First, the chrome-free surface treatment composition of one aspect of the present invention will be described in detail.

The chrome-free surface treatment composition of the present invention imparts excellent corrosion resistance, black degeneration and transparency, and is a chromium-free composition.

The chrome-free surface treatment composition according to the present invention is characterized in that it comprises, based on the total weight of the composition, a) 50 to 80% by weight of a water-soluble organic-inorganic hybrid resin, b) And d) 1 to 20% by weight of a metal chelate, e) 5 to 20% by weight of a curing agent, f) 1 to 10% by weight of a lubricant, and the balance of a solvent as the balance.

The water-soluble organic-inorganic hybrid resin a) functions to increase mutual physical properties by the reaction of conjugation of an organic resin with an inorganic binder, that is, an inorganic binder. Such a water-soluble organic- By weight to 80% by weight.

If the content of the water-soluble organic-inorganic hybrid resin contained in the chrome-free surface treatment composition according to the present invention is less than 50% by weight, it can not form a solid film and effectively prevents moisture penetration from the surface of the coated steel sheet requiring corrosion resistance Thus causing blackness, and there is a problem that the glossiness is reduced. On the other hand, if it exceeds 80% by weight, the content of the rust-inhibitive material, the inorganic metal sol and the curing agent to be added for the purpose of improving the corrosion resistance is relatively decreased, and it is difficult to ensure sufficient corrosion resistance.

As described above, the water-soluble organic-inorganic hybrid resin is obtained by the reaction of an organic resin and an inorganic binder, wherein the organic resin is preferably a water-soluble or water-dispersible resin having a carboxyl group or a hydroxy group. The organic resin not having a carboxyl group or a hydroxy group has a poor water dispersion stability and does not have a functional site capable of reacting with an inorganic binder or a coupling agent, so that a stable complexation reaction can not occur. Therefore, preferred organic resins in the present invention include water-soluble epoxy resins having carboxyl groups or hydroxy groups, epoxy-phosphate resins, epoxy-phosphate resins modified with acrylic or vinyl monomers, acrylic resins, vinyl resins, , An acrylic-urethane resin modified with an acrylic or vinyl monomer, a polyolefin resin, and an acrylic-modified polyolefin resin.

Of the organic resins, epoxy-phosphate resins, acrylic-urethane resins, and polyolefin resins may be modified with acrylic or vinyl monomers. As a method of denaturation, a method of radical polymerization by grafting an acrylic or vinyl monomer to an epoxy-phosphate resin, a polymerization method using an unsaturated acid such as maleic acid or fumaric acid, and the like can be given.

The organic resin as described above preferably has an average molecular weight (weight average molecular weight) of 7,000 to 15,000 and an acid value of 50 to 170 mgKOH / g. If the acid value of the organic resin used in the present invention is less than 50 mgKOH / g, the water dispersion stability is lowered and the functional site for the reaction with the inorganic binder or the coupling agent is insufficient to secure the required physical properties. On the other hand, an organic resin having an acid value of more than 170 mgKOH / g is excellent in water dispersion stability, but it is undesirable because it has a problem of deteriorating water resistance, corrosion resistance and alkali degreasing property after drying the film.

Further, the inorganic binder contained in the water-soluble organic-inorganic hybrid resin is for modifying the organic resin and is preferably composed of a silicon (Si) based compound and a molybdenum based compound.

Among the compounds forming the inorganic binder, the silicon (Si) -based compound is a material substantially involved in the modification of the organic resin, preferably 2- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane, 3- N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-glycyloxypropylmethyldiethoxysilane, 3-glycyloxypropyltriethoxysilane, (Aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-ureidopropyltrimethoxysilane and 3-ureidopropyltrialkoxysilane can be used as the silane coupling agent.

As the molybdenum compound, one or two or more kinds of molybdenum compounds selected from the group consisting of molybdenum oxide, sulfide, acetate, phosphate, carbide, chloride, boride and nitride may be used.

The ratio of the above-mentioned holding resin: silicon (Si) -based compound is preferably 2: 4: 100. In this case, if the weight ratio is less than 2, the content required for the composite of the organic resin and the inorganic binder is insufficient and it is difficult to secure the corrosion resistance. On the other hand, if the weight ratio is more than 4, the inorganic binder remaining after the reaction with the organic resin exists There is a problem that the corrosion resistance is reduced.

The content of the molybdenum compound is preferably 0.4 to 0.9% by weight based on the total weight of the composition. If the content of the molybdenum compound is less than 0.4% by weight, If it exceeds 0.9% by weight, the black discoloration is ensured but the corrosion resistance tends to be largely lowered, which is not preferable. On the other hand, when a molybdenum-based compound is used as an inorganic binder, it is not preferable to introduce the molybdenum compound in a blend form in a blend other than an inorganic binder because the corrosion resistance is greatly reduced.

The above-mentioned b) rust-preventive corrosion-resistant agent is included for the purpose of improving the corrosion resistance, and preferably one or two selected from the group consisting of a phosphoric acid-based rust inhibitor, Any kind of rust inhibitor may be used.

At this time, the rust-preventive and corrosion-resistant agent contained in the chromium-free surface treatment composition of the present invention is preferably contained in an amount of 1 to 10% by weight. When the content exceeds 10% by weight, On the other hand, when it is added in an amount of less than 1% by weight, there is no influence on the resistance to weathering, but it is difficult to secure the desired corrosion resistance.

The c) inorganic metal sol is added to improve the high corrosion resistance, and preferably one or more inorganic metal sol selected from the group consisting of silica sol, alumina sol, titania sol and zirconia sol is used as the inorganic metal sol .

At this time, the inorganic metal sol contained in the composition according to the present invention is preferably contained in an amount of 5 to 20% by weight. If the content of the inorganic metal sol is less than 5% by weight, corrosion resistance and weatherability of the coated steel sheet are deteriorated On the other hand, if it exceeds 20% by weight, there is a problem that the gloss of the coating film is lowered, the water resistance is lowered, the workability is lowered and the black pigment is lowered.

The inorganic metal sol contained in the present invention preferably has an average particle size of 5 to 30 nm. If the average particle size of the inorganic metal sol is less than 5 nm, a product having a strong alkalinity is generally used, which results in a poor water resistance and thus corrosion resistance and weatherability. On the other hand, in the case of a very low deposition amount of the composition, there is a problem that when the particle size included in the composition is too large, the pore is formed and the corrosion resistance is lowered. Therefore, the average particle size of the inorganic metal sol is preferably limited to 30 nm or less .

The d) metal chelating agent is added for the purpose of accelerating curing and securing high corrosion resistance. Preferably, the metal chelating agent is one or more chelating agents selected from the group consisting of silane, titanium and zirconium .

At this time, the metal chelating agent contained in the composition according to the present invention is preferably contained in an amount of 1 to 20% by weight. If the content is less than 1% by weight, the effect of improving corrosion resistance and weather resistance is not sufficient. And the effect of strengthening the coating is weak. On the other hand, if it exceeds 20% by weight, the chelate component which does not react and deteriorates the corrosion resistance is rather problematic, and the cost is too high, which is not preferable.

Examples of the silane chelating agent include vinyltriethoxysilane, 3-glycyloxyproprtrimethoxysilane, 3-glycyloxypropyltriethoxysilane, 3-glycyloxypropylmethyldimethoxysilane, N-2- ( Aminoethyl)) - 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and mixtures thereof. Titanium-based chelating agents include titanium acetylacetone Butoxy titanium ethyl acetoacetate, tetraisopropyl titanate, tetranormal butyl titanate, and mixtures thereof. Examples of the zirconium chelating agent include tetra-n-propyl zirconate, tetranormal-butyl zirconate, sodium, potassium, lithium, ammonium salts, triethanolamine zirconate, hexafluorozirconate, And mixtures thereof.

The curing agent (e) is a material that forms a dense coating through cross-linking with a functional group present in the resin to improve the solvent resistance, the corrosion resistance and the hardness of the coating film. The curing agent is preferably a melamine-based, carbodiimide- , Block isocyanate-based, aziridine-based, and oxazoline-based curing agents may be used.

At this time, the curing agent contained in the composition according to the present invention is preferably contained in an amount of 5 to 20% by weight. When the content is less than 5% by weight, sufficient crosslinking can not be achieved and securing the properties to be obtained by the addition of the curing agent On the other hand, when the content is more than 20% by weight, the stability of the solution is deteriorated due to excessive crosslinking, resulting in solidification over time.

The f) lubricant is added for imparting lubricity. Preferably, the lubricant is a paraffin wax, an olefin wax, a canvas wax, a polyester wax, a polyethylene wax, a polypropylene wax, a polyethylene-Teflon One or more waxes selected from the group consisting of waxes and polytetrax waxes can be used.

The lubricant contained in the composition according to the present invention is preferably contained in an amount of 1 to 10% by weight. When the content of the lubricant is less than 1% by weight, the slip property is insufficient, There is a problem that the material is broken. On the other hand, when the content exceeds 10% by weight, there is a problem in that the distribution of excessive lubricant particles on the surface of the coating causes a saddle phenomenon due to deterioration in corrosion resistance and excessive lubrication.

The chrome-free surface treatment composition according to the present invention may contain, as a remainder, a residual solvent amount in addition to the above-mentioned materials.

As the solvent, water, an organic solvent and the like can be used without limitation, but water is preferably used. Water is used to dilute resins and means deionized water or distilled water.

The chrome-free surface treatment composition according to the present invention can be used for the production of a hot-dip galvanized steel sheet.

The hot-dip galvanized steel sheet according to one aspect of the present invention is characterized in that a chromium-free surface treatment composition according to the present invention, that is, a water-soluble organic-inorganic hybrid resin, an anti-corrosive corrosion inhibitor, an inorganic metal sol, a metal chelating agent, And a chromium-free surface treatment composition composed of a residual solvent amount is applied to the remainder to form an anti-corrosion property, a black mark, and an improvement film.

As described above, when the corrosion-resistant, black marking and weatherability improving coatings are formed on the zinc-plated layer of the hot-dip galvanized steel sheet using the chromium-free surface treatment composition according to the present invention, the thickness of the coating is 0.3 to 2.0 m.

When the thickness of the dried film is less than 0.3 탆, the steel sheet is coated thinly on the mountain portion of the roughness to degrade the corrosion resistance. On the other hand, when the thickness exceeds 2.0 탆, there is a problem that the corrosion resistance after processing is deteriorated due to the thick film.

Thus, as described above, the surface-treated hot-dip galvanized steel sheet coated with the chrome-free surface treatment composition of the present invention exhibits excellent performance on the hot-dip galvanized steel sheet.

Hereinafter, the present invention will be described more specifically by way of examples. It should be noted, however, that the following examples are intended to illustrate the invention in more detail and not to limit the scope of the invention. The scope of the present invention is determined by the matters set forth in the claims and the matters reasonably inferred therefrom.

( Example  1) chromium- free  Preparation of surface treatment composition

Water-soluble organic-inorganic composite resin production

First, a water-soluble organic-inorganic hybrid resin which is a core of the chrome-free surface treatment composition according to the present invention is prepared.

To this end, organic resins are first prepared.

The organic resin was prepared by mixing 20 g of the ethylene acrylic acid copolymer resin and 5.56 g of triethylamine in 75.5 g of distilled water, and then heating the mixture to 80 to 100 캜 to prepare an ethylene acrylic acid copolymer resin.

Thereafter, 170 g of distilled water was mixed with 100 g of the produced ethylene acrylic acid copolymer resin and stirred sufficiently. 1.0 g of molybdic acid was added thereto, followed by stirring for 10 minutes. Thereafter, a silicon compound was added to the mixture, and the mixture was heated to 80 ° C for 1 hour, and then cooled to room temperature to prepare a water-soluble organic-inorganic hybrid resin.

chrome- free  Preparation of surface treatment composition

To the 81 g of the water-soluble organic-inorganic hybrid resin prepared above, 4 g of phosphoric acid-based rust-inhibiting corrosion resistant agent, 5 g of silica sol, 4 g of titanium metal chelate, 5 g of carbodiimide curing agent and 1 g of a polyethylene lubricant were added, A composition was prepared.

( Example  2) Specimen preparation for test

Test specimens for evaluating the corrosion resistance of the chrome-free surface treatment composition prepared in Example 1 were prepared as follows.

The surface of the chromium-free surface treatment composition prepared in Example 1 was coated on a bar (BAR) at a coating amount of 1 μm after cutting off the oil content by cutting the hot-dip galvanized steel sheet (Zn-Al-Mg) into 7 cm × 15 cm - Coating and curing under conditions of PMT 150 ± 30 ℃ to prepare specimens.

( Example  3) Evaluation of physical properties

The physical properties of the cro-free surface treatment composition prepared in Example 1 were evaluated according to the following criteria after testing the respective physical properties to be evaluated.

- Darkness Modification: The color change of the specimen before and after the test was observed by allowing it to stand for 120 hours in a thermo-hygrostat maintained at 50 ° C and 95% RH. At this time, evaluation criteria were evaluated as ΔE <2: excellent, 2 <ΔE <3: good, ΔE> 3: poor.

- Plate corrosion resistance: Based on the method specified in ASTM B117, the rate of white rusting of the steel sheet was measured over time after treating the chrome-free surface treatment composition. The evaluation criteria were as follows: Excellent: Whitehead occurrence time was 144 hours or more, good: Whitehead occurrence time was 96 hours or more and 144 hours or less, Bad: Whitehead occurrence time was 96 hours or less.

- Corrosion resistance of machined part: The steel plate treated with the chrome-free surface treatment composition was pushed up to a height of 6 mm using an Erichsen tester, and the extent of occurrence of white rust was measured 48 hours later. At this time, the evaluation criteria were as follows: excellent: less than 5% of white rust occurrence after 48 hours, poor: more than 5% of white rust occurrence after 48 hours.

The surface of the steel sheet treated with the chrome-free surface treatment composition was coated with vaseline, and the color difference before and after coating with vaseline was observed. At this time, evaluation criteria were as follows: Excellent: Less than 2 color difference, Bad: More than 2 color difference.

( Experimental Example  1) Silicon ( Si ) Changes of physical properties according to kind and content of compound

In order to change the physical properties of the chromium-free surface treatment composition prepared according to Example 1 according to the kind and content of the contained silicon (Si) compound, as shown in Table 1 below, Each chromium-free surface treatment composition was prepared by different kinds and contents.

Thereafter, test specimens (Comparative Examples and Inventive Examples 1 to 34) were prepared in the same manner as in Example 2, using each of the chrome-free surface treatment compositions prepared above, and then evaluated for physical properties (Flat plate corrosion resistance), and the results thereof are shown in Table 1 below.

division Silicon (Si) based compound content (% by weight) reputation
Corrosion resistance A B C D E F G H I J K Comparative Example 1 - - - - - - - - - - - Bad Inventory 1 One - - - - - - - - - - Good Inventory 2 - One - - - - - - - - - Great Inventory 3 - - One - - - - - - - - Good Honorable 4 - - - One - - - - - - - Great Inventory 5 - - - - One - - - - - - Good Inventory 6 - - - - - One - - - - - Great Honorable 7 - - - - - - One - - - - Good Honors 8 - - - - - - - One - - - Good Proposition 9 - - - - - - - - One - - Good Inventory 10 - - - - - - - - - One - Great Exhibit 11 - - - - - - - - - - One Good Inventory 12 0.5 0.5 - - - - - - - - - Good Inventory 13 0.5 - - 0.5 - - - - - - - Good Inventory 14 - 0.5 - - - 0.5 - - - - - Great Honorable Mention 15 - - - 0.5 - 0.5 - - - - - Good Inventory 16 - - - - 0.5 - 0.5 - - - - Good Inventory 17 - - - - - 0.5 - - - 0.5 - Great Inventory 18 - - 0.5 - - 0.5 - - - - - Good Evidence 19 - - - - - - 0.5 - - 0.5 - Good Inventory 20 0.5 - - - - - - - - 0.5 - Good Inventory 21 - - - - - - - - - 0.5 0.5 Good Inventory 22 - - - 0.5 - - - - 0.5 - - Good Inventory 23 - - - - 0.5 - - 0.5 - - - Good Honors 24 - - - - - - - 0.5 - - 0.5 Good Honors 25 - 0.5 0.5 - - - - - - - - Great Evidence 26 - - 0.5 - - - - - - - 0.5 Good Honors 27 - - - - - - 0.5 - 0.5 - - Good Evidence 28 - - - - 0.5 - - - 0.5 - - Good Evidence 29 - 0.5 - 0.5 - - - - - - - Great Inventory 30 - 0.5 - - - - - - - - 0.5 Good PROPERTIES 31 0.5 - 0.5 - - - - - - - - Good Exhibit 32 - - - - - - - - 0.5 0.5 - Good PROPERTIES 33 - 0.5 - - 0.5 - - - - - - Good PROPOSITION 34 - - - - - - 0.5 0.5 - - - Good

(In the above Table 1, A to K are silicon (Si) -based compounds such as A: 2- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane, B: 3-glycyloxypropyltrimethoxysilane, C: 3-glycyloxypropylmethyldiethoxysilane, D: 3-glycyloxypropyltriethoxysilane, E: N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, F: N- Aminopropyltrimethoxysilane, G: N-2- (aminoethyl) -3-aminopropyltriethoxysilane, H: 3-aminopropyltrimethoxysilane, I: 3 -Aminopropyltriethoxysilane, J: 3-ureidopropyltrimethoxysilane and K: 3-ureidopropyltrialkoxysilane.)

As shown in Table 1, Comparative Example 1 in which no silicon (Si) compound was added at all showed poor results in the evaluation of plate corrosion resistance.

On the other hand, in the case of Inventive Examples 1 to 34 in which a composite was formed by mixing the organic resin produced according to the present invention with a silicon (Si) -based compound, the plate corrosion resistance was good or excellent. Particularly, in the case of the test specimen treated with the chromium-free surface treatment composition prepared according to the composition of Inventive Example 17, the white rust area generated after 144 hours or more was the best with less than 2%.

( Experimental Example  2) silicon ( Si ) Based compound and the silicon ( Si ) Change of physical properties according to weight ratio of system compound and organic resin

(Si) based compound of Inventive Example 17 showing the best flat plate corrosion resistance in Experimental Example 1 and the ratio of the content of the silicon (Si) based compound to the weight ratio of the silicon (Si) based compound to the organic resin Were observed.

To this end, the composition of silicon (Si) based compound of Inventive Example 17 was mixed at the content ratios shown in Table 2 below. Each water-soluble organic-inorganic hybrid resin was prepared in the same manner as in Example 1, except that the weight ratio of each silicon-based compound to the organic resin was different. A chrome-free surface treatment composition was prepared by adding 4 g of a phosphoric acid-based rust-inhibiting corrosion resistant agent, 5 g of a silica sol, 4 g of a titanium-based metal chelating agent, 5 g of a carbodiimide curing agent and 1 g of a polyethylene lubricant to 81 g of a resin.

Thereafter, the test specimens (Comparative Examples 2 to 9 and Examples 35 to 46) were produced in the same manner as in Example 2, using each of the above-mentioned chrome-free surface treating compositions, Evaluation was carried out, and the results are shown together in Table 2 below. At this time, a polyolefin resin having an acid value of 100 mgKOH / g was used as an organic resin,

division Organic resin and
Concentration of Cone Compound Silicone compound content ratio reputation
Corrosion resistance Processing section
Corrosion resistance To Moon F J Comparative Example 2 100: 1 20 80 Bad × Bad Comparative Example 3 100: 1 40 60 Good × Bad Comparative Example 4 100: 1 60 40 Good × Bad Comparative Example 5 100: 1 80 20 Bad × Good Practice 35 100: 2 20 80 Good ○ Good EXPERIENCE 36 100: 2 40 60 Good ○ Good Honors 37 100: 2 60 40 Great ○ Good Honors 38 100: 2 80 20 Good ○ Good EVENTS 39 100: 3 20 80 Great ○ Good Honors 40 100: 3 40 60 Good ○ Good Inventory 41 100: 3 60 40 Great ○ Good Honors 42 100: 3 80 20 Good ○ Good Honors 43 100: 4 20 80 Great ○ Good Honors 44 100: 4 40 60 Great ○ Good Opportunity 45 100: 4 60 40 Great ○ Good Honors 46 100: 4 80 20 Good ○ Good Comparative Example 6 100: 5 20 80 Great × Good Comparative Example 7 100: 5 40 60 Good × Good Comparative Example 8 100: 5 60 40 Good × Good Comparative Example 9 100: 5 80 20 Good × Good

(In Table 2, F and J are F: N-2- (aminoethyl) -3-aminopropyltrimethoxysilane and J: 3-ureidopropyltrimethoxysilane as silicon (Si) .)

As shown in Table 2, in the case of Comparative Examples 2 to 9 in which the weight ratio between the organic resin constituting the water-soluble organic-inorganic hybrid resin and the silicon (Si) -based compound was 2 to 4: 100, One or more of the sub-corrosion resistance and anti-corrosion properties were shown to result in heat.

On the other hand, in Examples 35 to 46 in which the weight ratio between the organic resin and the silicon (Si) -based compound was 2 to 4: 100, all the results were better than those in the physical properties.

( Experimental Example  3) Change of physical properties according to content of molybdenum compounds

The water-soluble organic-inorganic hybrid resin according to Inventive Example 45 showing excellent results in the evaluation of properties in Experimental Example 2 was used, and the content of the molybdenum compound in the inorganic binder added to the water- Changes in physical properties were observed.

To this end, first, a mixture was prepared by adding or not adding the molybdenum compound to the organic resin while changing the content of the molybdenum compound, and then a silicon (Si) compound having the composition of Inventive Example 45 of Experimental Example 2 was added , And each of the water-soluble organic-inorganic hybrid resins was prepared in the same manner as in Example 1. Then, 4 g of phosphoric acid-based rust-inhibiting corrosion resistant agent, 5 g of silica sol, 4 g of titanium-based metal chelating agent, 5 g of carbodiimide curing agent and 1 g of polyethylene-based lubricant were added to 81 g of each of the water-soluble organic- Of the chromium-free surface treatment composition.

Thereafter, the test specimens (Comparative Examples 10 to 12 and Inventive Examples 47 to 48) were produced in the same manner as in Example 2 above using each of the above-mentioned chrome-free surface treating compositions, The results are shown in Table 3 below. At this time, molybdic acid was used as the molybdenum compound.

On the other hand, in the case of Comparative Example 10, the molybdenum compound was not added in the process of preparing the water-soluble organic-inorganic hybrid resin, and when 0.9 wt% was added to the solution preparation step, that is, the rustproofing agent, The specimen was prepared using a chrome-free surface treatment composition.

division Molybdic acid
Content (% by weight) Plate corrosion resistance Processing section
Corrosion resistance Black degeneration To Moon Comparative Example 10 - Bad × Great Bad Comparative Example 11 0.3 Great × Bad Bad Honors 47 0.4 Great ○ Good Great Honors 48 0.9 Great ○ Good Great Comparative Example 12 1.0 Good × Bad Great

As shown in Table 3, in the case of Inventive Examples 47 and 48 in which a molybdenum compound was added as proposed in the present invention, all of the properties were better than those in Examples. On the other hand, Comparative Example 10 in which the molybdenum compound was not added in the step of preparing the organic-inorganic hybrid resin and the molybdenum compound was added in the solution preparation step showed poor results in all properties except the weathering.

These results show that when the molybdenum compound is added together in the step of preparing the organic-inorganic hybrid resin, the added molybdenum compound is uniformly distributed in the organic-inorganic hybrid resin, However, since the molybdenum compound precipitates on the surface of the steel sheet when the coating is formed, when the molybdenum compound is dissolved in the salt solution due to the reaction with the resin, .

However, in the case of Comparative Examples 11 and 12 in which the content ratio of the molybdenum compound was not satisfied in the range of 0.4 to 0.9% by weight in the step of preparing the organic-inorganic hybrid resin, the plate corrosion resistance and physical properties of the substrate were secured to some extent, The corrosion resistance and the properties of the blackening resistance were very good.

( Experimental Example  4) Anticorrosion  Change of physical properties according to content

In preparing the chromium-free surface treatment composition using the water-soluble organic-inorganic hybrid resin according to the present invention 48, which has shown excellent results in the evaluation of properties in Experimental Example 3, the change in physical properties according to the content of the rust- Respectively.

In preparing the chromium-free surface treatment composition in the same manner as in Example 1, using the water-soluble organic-inorganic hybrid resin prepared according to the preparation 48 of the present invention, 81 g of the water-soluble organic- , 5 g of silica sol, 5 g of a titanium-based metal chelating agent, 5 g of a carbodiimide-based curing agent and 1 g of a polyethylene-based lubricant were added to prepare respective chromium-free surface treatment compositions.

Thereafter, test specimens (Comparative Examples 13 to 14 and Inventive Examples 49 to 52) were prepared in the same manner as in Example 2, using each of the chrome-free surface treatment compositions prepared above, , And the results are shown in Table 4 below.

division Rust anti-corrosion agent
Content (% by weight) reputation
Corrosion resistance Processing section
Corrosion resistance Black degeneration To Moon Comparative Example 13 0.5 Bad × Great Bad Honorable 49 1.0 Good ○ Great Great Honors 50 3.0 Good ○ Good Great EXPERIENCE 51 7.0 Great ○ Good Great Honors 52 10 Great ○ Good Great Comparative Example 14 11 Bad × Bad Bad

As shown in Table 4, when the rust-preventive corrosion-resistant agent was added according to the proposal of the present invention (Examples 49 to 41), all of the properties showed better results.

On the other hand, when too little rust-preventive corrosion inhibitor was added (Comparative Example 13), all of the properties except for the weathering resistance showed poor results, and when too much addition was added (Comparative Example 14), all properties were poor.

( Experimental Example  5) Weapons Metal sol  Change of physical properties according to content

In preparing the chromium-free surface treatment composition using the water-soluble organic-inorganic hybrid resin according to the present invention 48, which has shown excellent results in the evaluation of properties in Experimental Example 3, the physical property changes depending on the content of the inorganic metal sol added thereto Respectively.

In preparing the chromium-free surface treatment composition in the same manner as in Example 1 using the water-soluble organic-inorganic hybrid resin prepared in Preparation 48, 4 g of a phosphoric acid-based rust inhibitor was added to 81 g of the water- 2 to 21 g of a silica sol, 5 g of a titanium-based metal chelating agent, 5 g of a carbodiimide-based curing agent and 1 g of a polyethylene-based lubricant were added to prepare respective chromium-free surface treatment compositions.

Thereafter, the test specimens (Comparative Examples 15 to 16 and Inventive Examples 53 to 56) were produced in the same manner as in Example 2, using each of the chrome-free surface treating compositions prepared above, , And the results are shown in Table 5 below.

division Inorganic metal sol
Content (% by weight) reputation
Corrosion resistance Processing section
Corrosion resistance Black degeneration To Moon Comparative Example 15 2 Good × Great Bad Honors 53 5 Good ○ Great Great Honors 54 10 Good ○ Great Great Honors 55 15 Good ○ Good Great Honors 56 20 Good ○ Good Great Comparative Example 16 21 Good ○ Bad Bad

As shown in Table 5, it was confirmed that the inorganic metal sol contained in the chrome-free surface treatment composition affects the corrosion resistance, black marking and glossiness of the processed portion. That is, as the content of the inorganic metal sol is increased, the corrosion resistance of the processed part is improved, but when the content is too much, the result is poor in the blackness and the smoothness.

The inorganic metal sol is composed of a porous inorganic material. Such a porous inorganic material tends to absorb moisture, and if the content is too high, it is understood that the internal blackness and the weatherability are poor. From these results, it is preferable that the content of the inorganic metal sol capable of securing the corrosion resistance of the processed portion at a level of good weathering resistance is 5 to 20% by weight.

( Experimental Example  6) At the mountain  Changes in physical properties

In preparing the chromium-free surface treatment composition using the water-soluble organic-inorganic hybrid resin according to the present invention 48, which is excellent in the evaluation of physical properties in Experimental Example 3, the organic resin The change of physical properties according to the acid value was observed.

In preparing the chrome-free surface treatment composition in the same manner as in Example 1 using the water-soluble organic-inorganic hybrid resin prepared according to the present invention 48, an organic resin having an acid value of 40 to 180 mg KOH / g was used 4 g of a phosphate-based rust inhibitor, 4 g of a silica sol, 5 g of a titanium-based metal chelating agent, 5 g of a carbodiimide-based curing agent and 1 g of a polyethylene-based lubricant were added to 81.5 g of the water- .

Thereafter, test specimens (Comparative Examples 17 to 18 and Inventive Examples 57 to 59) were produced in the same manner as in Example 2, using each of the chrome-free surface treatment compositions prepared above, And the results are shown in Table 6 below.

division Organic resin
Acid value (mg KOH / g) reputation
Corrosion resistance Processing section
Corrosion resistance Black degeneration To Moon Comparative Example 17 40 Good × Bad Bad Honors 57 50 Great ○ Great Good Honors 58 100 Great ○ Great Good Evidence 59 170 Good ○ Good Good Comparative Example 18 180 Bad × Bad Bad

As shown in Table 6, when the acid value of the organic resin used was less than 50 mgKOH / g (Comparative Example 17), there were few functional groups reacting with the inorganic binder, resulting in poor corrosion resistance, When the acid value of the organic resin was too low (Comparative Example 18), the water repellency was lowered as the hydrophilic functional group was contained too much, resulting in poor physical properties.

On the other hand, Examples 57 to 59 using an organic resin having an acid value in the range of 50 to 170 mg KOH / g showed better results in all properties.

( Experimental Example  7) Change of physical properties according to content of hardener

In the preparation of the chromium-free surface treatment composition using the water-soluble organic-inorganic hybrid resin according to Example 48, which showed excellent results in the property evaluation in Experimental Example 3, the change in physical properties according to the content of the curing agent added thereto was observed Respectively.

In preparing the chromium-free surface treatment composition in the same manner as in Example 1, using the water-soluble organic-inorganic hybrid resin prepared in Preparation 48, 81.5 g of the water-soluble organic-inorganic hybrid resin was mixed with 4 g of a phosphate- 4 g of silica sol, 5 g of a titanium-based metal chelating agent, 4 to 21 g of a carbodiimide-based curing agent and 1 g of a polyethylene-based lubricant were added to prepare respective chromium-free surface treatment compositions.

Thereafter, test specimens (Comparative Examples 19 to 20 and Inventive Examples 60 to 62) were prepared in the same manner as in Example 2, using each of the chrome-free surface treatment compositions prepared above, , And the results are shown in Table 7 below.

division Hardener
Content (% by weight) reputation
Corrosion resistance Processing section
Corrosion resistance Black degeneration To Moon Comparative Example 19 4 Good × Bad Bad Honor 60 5 Great ○ Great Good Evidence 61 10 Great ○ Great Good PROPERTIES 62 20 Good ○ Good Good Comparative Example 20 21 Bad × Bad Bad

As shown in Table 7, when the curing agent was added according to the proposal of the present invention (Examples 60 to 62 of the present invention), all of the physical properties showed better results.

On the other hand, when too little curing agent was added (Comparative Example 19), all properties except for plate corrosion resistance showed poor results, and when too much was added (Comparative Example 20), all properties were poor.

( Experimental Example  8) Change of physical properties according to the content of lubricant

In the preparation of the chrome-free surface treatment composition using the water-soluble organic-inorganic hybrid resin according to Example 48, which showed excellent results in the evaluation of properties in Experimental Example 3, the change in physical properties according to the content of the lubricant added was observed Respectively.

In preparing the chromium-free surface treatment composition in the same manner as in Example 1, using the water-soluble organic-inorganic hybrid resin prepared in Preparation 48, 81.5 g of the water-soluble organic-inorganic hybrid resin was mixed with 4 g of a phosphate- 4 g of silica sol, 5 g of a titanium-based metal chelating agent, 5 g of a carbodiimide-based curing agent and 0.5 to 11 g of a polyethylene-based lubricant were added to prepare respective chromium-free surface treatment compositions.

Thereafter, test specimens (Comparative Examples 21 to 22 and Inventive Examples 63 to 65) were produced in the same manner as in Example 2, using each of the chrome-free surface treatment compositions prepared above, , And the results are shown in Table 8. &lt; tb &gt;&lt; TABLE &gt;

division slush
Content (% by weight) reputation
Corrosion resistance Processing section
Corrosion resistance Black degeneration To Moon Comparative Example 21 0.5 Good × Bad Bad Proposition 63 One Great ○ Great Good Honors 64 5 Great ○ Great Good Honorable Mention 65 10 Good ○ Good Good Comparative Example 22 11 Bad × Bad Bad

As shown in Table 8, when the lubricant was added according to the proposal of the present invention (Examples 63 to 65), all of the properties showed better results than those of Examples.

On the other hand, when too little lubricant was added (Comparative Example 21), all properties except for plate corrosion resistance showed poor results. In case of adding too much lubricant (Comparative Example 22), all properties were poor.

( Experimental Example  9) Property change according to film thickness

In the coating of the hot-dip galvanized steel sheet using the chrome-coating surface treatment composition according to the present invention, the change in physical properties according to the thickness of the dried coating was observed.

To prepare the chrome-free surface treatment composition in the same manner as in Example 1 using the water-soluble organic-inorganic hybrid resin prepared according to Example 48, which was excellent in the evaluation of properties in Experimental Example 3, , 4 g of a phosphoric acid-based rust inhibitor, 4 g of a silica sol, 5 g of a titanium-based metal chelating agent, 5 g of a carbodiimide curing agent and 1 g of a polyethylene-based lubricant were added to 81.5 g of the water-soluble organic-inorganic hybrid resin to prepare a chrome- Respectively.

Thereafter, the test specimens (Comparative Examples 23 to 24 and Examples 66 to 68) were prepared in the same manner as in Example 2, except that the chromium-free surface treatment composition prepared above had a coating amount of 0.2 to 2.0 μm, Then, the physical properties evaluation described in Example 3 was carried out, and the results are shown in Table 9 below.

division Dry film
Thickness (μm) reputation
Corrosion resistance Processing section
Corrosion resistance Black degeneration To Moon Comparative Example 23 0.2 Bad × Bad Bad Proof 66 0.3 Great ○ Great Good Honorable Mention 67 1.0 Great ○ Great Good Honors 68 2.0 Good ○ Good Good Comparative Example 24 2.1 Good × Good Good

As shown in Table 9, in the case of forming a coating film having a thickness as proposed in the present invention (Examples 66 to 68), all of the physical properties showed better results.

On the other hand, when the formed film was too thin (Comparative Example 23), all of the physical properties showed poor results, and when the formed film was too thick (Comparative Example 24), the processed portion had poor corrosion resistance.

Claims (12)

With respect to the total weight of the composition,
a) 50 to 80% by weight of a water-soluble organic-inorganic hybrid resin,
b) rustproofing corrosion resistance 1-10% by weight,
c) 5 to 20% by weight of an inorganic metal sol,
d) from 1 to 20% by weight of a metal chelate,
e) 5 to 20% by weight of a curing agent,
f) 1 to 10% by weight of a lubricant, and the remainder of the solvent,
The chromium-free surface treatment composition according to claim 1, wherein the water-soluble organic-inorganic hybrid resin (a) is obtained by reaction between an organic resin and an inorganic binder, and the inorganic binder is composed of a silicon (Si) compound and a molybdenum compound.
delete The method according to claim 1,
The organic resin may be a water-soluble epoxy resin having a carboxyl group or a hydroxyl group, an epoxy-phosphate resin, an epoxy-phosphate resin modified with an acrylic or vinyl monomer, an acrylic resin, a vinyl resin, a water- Free surface treatment composition comprising at least one member selected from the group consisting of an acrylic-urethane resin, a polyolefin resin, and an acryl-modified polyolefin resin modified with a polyolefin resin.
The method according to claim 1,
The silicon (Si) -based compound may be at least one selected from the group consisting of 2- (3,4 epoxycyclohexyl) -ethyltrimethoxysilane, 3-glycyloxypropyltrimethoxysilane, 3-glycyloxypropylmethyldiethoxysilane, 3- (Aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (amino) -3-aminopropyltrimethoxysilane, N-2- Ethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-ureidopropyltrimethoxysilane and 3-ureidopropyltrialkoxysilane. And the molybdenum compound includes at least one selected from the group consisting of molybdenum oxide, sulfide, acetate, phosphate, carbide, chloride, boride and nitride, Chrome-free surface treatment composition .
The method according to claim 1,
Wherein the ratio of the holding resin to the silicon (Si) based compound is 2 to 4: 100, and the molybdenum based compound is contained in an amount of 0.4 to 0.9% by weight based on the total weight of the composition.
The method according to claim 1,
The chromium-free surface treatment composition of claim 1, wherein the rust-preventive corrosion-resistant agent comprises at least one selected from the group consisting of a phosphoric acid-based rust inhibitor, a fluorine-based rust inhibitor, a vanadium-based rust inhibitor, a cerium salt-based rust inhibitor and a serine salt-based rust inhibitor.
The method according to claim 1,
The c) inorganic metal sol comprises at least one member selected from the group consisting of silica sol, alumina sol, titania sol, and zirconia sol.
8. The method of claim 7,
Wherein the inorganic metal sol has an average particle size of 5 to 30 nm.
The method according to claim 1,
The chromium-free surface treatment composition according to claim 1, wherein the metal chelating agent (d) comprises one or more selected from the group consisting of silane, titanium and zirconium.
The method according to claim 1,
The chromium-free surface treatment composition according to claim 1, wherein the curing agent is one or more selected from the group consisting of melamine-based, carbodiimide-based, block isocyanate-based, aziridine-based and oxazoline-based curing agents.
The method according to claim 1,
The f) lubricant may be one or more selected from the group consisting of paraffin wax, olefin wax, carnauba wax, polyester wax, polyethylene wax, polypropylene wax, polyethylene-teflon wax and polytetrap wax A chromium-free surface treatment composition comprising two or more chromium-free surface treatment compositions.
A coating layer of the chromium-free surface treatment composition according to any one of claims 1 to 11 is formed on one side or both sides of a hot-dip galvanized steel sheet,
Wherein the coating layer has a dry film thickness of 0.3 to 2.0 占 퐉.